By Malachi Motano
Whereas the two major passion fruits grown in Kenya are Yellow and Purple varieties, Kenya Agricultural and Livestock Research Organization (KALRO) over the years has developed a few more commercial hybrid varieties with superior qualities. They include KPF4-very sweet, KPF11 – yielding much higher than KPF4 and KPF12 – also yielding higher than KPF4 however, James Njeru Ndirangu a farmer in Nyeri is attempting another variety, still a hybrid but popular in India.
Dubbed Kaveri, is a cross between purple and yellow varieties, an F1 high yielding hybrid variety which takes shorter time to. Its fruits are ovoid to round and purple dotted in colour. The fruits are large with 30-35 % juice, 12% total sugars and about 3% acidity.
The average fruit weight ranges between 90-100 g. Each plant bears 40-60 fruits per harvest and the average yield of a grown up orchard is around 60-70 tonnes per year. Its fruit yield is around 200 8 tonnes per ha over a three-year cropping period. Fruits contain 25-30 per cent juice, 11.5-12.0 percent sugars and 3.0-3.5 mg citric acid/100ml of Juice. It is tolerant to brown leaf spot, wilt, and collar rot, root-knot nematode and thrips. It is also tolerant to Alternaria leaf spot, Fusarium collar rot and nematodes.
Morphologically, it is similar to yellow passion fruits but vines produces purple fruit. Fruits size is bigger than purple passion fruits and possess moderate intensity of aroma.
Kaveri variety is popular in Karnataka, Kerala, Tamilnadu and North Eastern States in India where it was developed at the Central Horticultural Experiment Station, Chettalli in 1986 and is now finding its way into Kenyan soil.
In terms of ecological requirement, it thrives in deep well drained soils with a PH range of 6.0-7.0, and should also be rich in organic matter. Kaveri also does in an altitude range of between 1200-2000M ASL, with annual rainfall of about 900-2000mm for an optimal production of this crop. Excess rainfall leads to poor fruit sett and also encourages diseases. Temperatures should range between 18-28 degrees centigrade is sufficient.
“I am confident that Kaveri can do well here, the altitude is around 1700 last time I checked it was 1750 with rainfall of up to 1004mm. Temperatures ranges from 17.1 degrees centigrade. If you compare this to the published growth conditions, in Nyeri we are at average,” says Njeru
To get Kaveri hybrid variety, Njeru says he employs grafting technology since it multiplies hybrid varieties on disease resistance rootstock and is resistant to nematode infestation and diseases hence good for rootstalk of hybrid varieties.
“Yellow passion fruit can be sown either in March or October for raising seedlings depending on the availability of the seed. The seedlings can be raised in seedbeds or plots the plants become ready for planting in three months. They will have developed enough to provide rootstock,” says explains.
He says scions from healthy young vines are preferred to those from mature plants. Generally both stock and scions should be of a pencil thickness for grafting. The diameter of the selected scion should match that of the rootstock. Cleft graft, whip graft or side wedge graft methods can be used.
A cleft graft is used for top working new cultivars on existing trees. It is used for relatively small branches and done when the stock is dormant and cracks easily. Two scions are inserted on either side of the branch and the cambium lined up along the outer edge. Whip grafting is done when corresponding cuts through rootstock and scion material are joined end to end and then bound. It is commonly used for bench grafting fruit trees. When the scion is smaller than the rootstock, wedge grafts are made on one side of the rootstock.
According to Njeru, it can take two and a half months for the root stalk to be ready for grafting if it is in a greenhouse. “Grafting period will depend on the number of plants and the grafters available. They will then require another one week at the green house and placed under the required conditions, they will be ready for planting. Once planted will only take like one month to flower and produce fruits,” Njeru explains.
The whole process thus from planting the parent plant for the rootstalk , grafting then planting till it gets ready for the market Njeru says can take only four months and not eight to one year taken by the normal yellow and purple parent passion varieties. “The Kaveri hybrid variety takes shorter time to mature,” says Njeru.
Mr. Njeru intends to grow 20,000 Kaveri passion hybrid variety seedlings, but is still would like to test on different locations, with different soils after the first trial at his farm in Tetu proved successful.
“I tried with only four seedlings and was successful. You know Kenya’ soil being different from Indian soil, the fruit must undergo several evaluations which include size, taste, colour among others to ensure that it compares the same with those in India-the target market. Therefore I am identifying other regions for example Nanyuki for further trials to establish if the production can be the same. I want to try with about 2000 seedling,” says Njeru.
Generally, seedlings and grafted passion plants are always very vigorous. The fruit vines originating from grafting starts fruiting faster (7-6 months) while plants raised from seeds start fruiting from 10-12 months.
There are two major passion fruit varieties; Purple and Yellow varieties when ripe. The purple variety is quite acidic, and tasty and juiciness varies. It has a strong aromatic scent and is round in shape. This variety is suited to the subtropical regions. While the Yellow variety is yellow one is oval in shape and less aromatic. This variety is adapted to the tropics, thus does very well in Kenya. Both varieties are usually green in colour before ripening.
With the yellow being distinguished as P. edulis var.flavicarpa. Hybrids have been developed from their crosses, which have yielded several intermediates between the two forms.
The hybrids of yellow and purple passion varieties have been developed in Brazil, Australia and South Africa to combine the desirable characteristics of both the forms of passion fruits.
